Behaviour and configurable delegator for asset price lookups.
Ships with two built-in implementations:
Rujira.Prices.Default— oracle → FIN book mid-price fallbackRujira.Prices.Noop— returns 0 (useful for tests)
Consumers can override via application env:
config :rujira_ex, prices: MyApp.CustomPricesDefaults to Rujira.Prices.Default.
Cache TTL
The default implementation memoizes prices using the global cache TTL.
See Rujira.cache_ttl/0.